The present invention is directed to a dust collector for a sewing machine and more particularly to a dust collector capable of automatically collecting waste cloth, waste threads, dust and other waste generated during a sewing operation, particularly a sewing operation utilizing an overseaming machine.
Conventional dust collector devices for sewing machines are generally comprised of a blower and a dust collecting box. One type of dust collector is provided with an additional motor-blower combination independent of the clutch motor adapted to drive the sewing machine. Generally, this type of dust collector is bulky and inconvenient to install relative to the conventional sewing machine drive. Another type of dust collector utilizes a blower which receives its power from the free end of the sewing machine clutch motor during normal rotation thereof. However, with this type of arrangement, the blower is usually provided with rotary blades which have a speed of rotation higher than that of the sewing machine clutch motor and which generally have an outer diameter larger than that of the clutch motor. In this type of arrangement, the clutch motor is primarily adapted to drive the sewing machine and when the blower is connected to the clutch motor it is necessary to provide a speed amplifier transmission arrangement between the free end of the clutch motor and the blower blades. Such an arrangement makes the overall structure very complicated while still producing an erratic output speed for the blower.
Furthermore, in both of the dust collecting arrangements discussed above, the blower is continuously operated regardless of the need for an actual dust collecting operation so that uncomfortably high noise levels are always generated by the blower while generally it is only necessary to carry out the dust collecting operation during only 20% to 30% of the actual sewing time.
Another type of dust collector for a sewing machine is disclosed in U.S. Patent application Ser. No. 313,141 filed on Oct. 20, 1981 U.S. Pat. No. 4,375,712 and assigned to the assignee of the present application. In that arrangement two collection boxes are utilized, one for thread scraps and the other for fabric scraps. Different diameter suction hoses are required for each box and the suction-blower motor is designed to operate only when the sewing machine is being operated and then continuously with the operation of the sewing machine.